Dangerous heat to challenge records in southwestern US by next week

Heat will build to dangerous, record-challenging levels in the southwestern United States this Father's Day weekend and continue through much of next week.

While heat is expected during the summer in the Southwest, temperatures climbing to 5 to 15 degrees Fahrenheit above average will translate to highs reaching the 110s to near 120 in the deserts, according to AccuWeather Senior Meteorologist Ken Clark.

"The weather pattern will bring the hottest weather of the year so far to many areas in the Southwest," Clark said.

Cities poised to have their hottest weather this year and challenge record highs include Phoenix, Las Vegas and Sacramento, California. Downtown Los Angeles can expect multiple days with highs near 90. Even Flagstaff, Arizona, at an elevation above 6,000 feet, will climb into the 90s during many days next week.

Intense June sunshine, light winds and the temperatures anticipated can be a lethal combination. Heat is the leader in direct fatalities related to weather, according to the National Weather Service.

People are urged to avoid strenuous activity during the midday and afternoon hours and drink plenty of fluids to reduce the risk of heat exhaustion and heatstroke.

Consuming excess alcohol can increase the risk of and accelerate dehydration, according to the Centers for Disease Control (CDC). Be sure to check frequently on young children and the elderly as they are most susceptible to the heat.

Air conditioner usage will push energy demands to high levels in the coming days over the region. People can conserve energy by turning off the unit when no one is home or by closing doors or vents in rooms that are not in use.

The combination of light winds and heat can lead to a buildup of pollutants in the atmosphere in the coming days. The conditions could cause difficulties for those with respiratory problems.

Meanwhile, air temperatures at the Southern California beaches will be 10 to 30 degrees lower than inland areas most days through Tuesday. Surf temperatures range from the upper 50s to near 70 along Southern California.

The heat will prompt another surge of melting snow over the high country. While the heat can make for prime whitewater rafting, the cold and fast-flowing water can be dangerous.

Water temperatures of some mountain streams and lakes are still in the 30s and 40s. Cold water shock and hypothermia can hit anyone, at any age, no matter how physically fit.

Use caution with outdoor power equipment, vehicles and open flames in the hot and dry conditions.

Despite the ample rain this winter, heat, sunshine and dry air will raise the risk of wildfire ignition and spread. Never throw burning cigarettes outside and properly extinguish camp fires and barbecue grills. Avoid parking a vehicle over high brush as the hot exhaust system can lead to a fire.

The vast majority of the West will be free of rain through next week, according to AccuWeather Senior Meteorologist Michael LeSeney.

"A couple of storms from the Pacific will move ashore into next week," LeSeney said. "However, clouds, showers and cooler air associated with these storms will barely impact the Northwest."

Only very spotty thunderstorms may pop up over the Sierra Nevada and the southern Rockies during the late-afternoon hours next week.

There is no sign of the monsoon setting up in the southwestern U.S. through next week, since humidity levels are likely to remain very low.